甲状腺激素促进肿瘤细胞增殖及血管新生信号通路的研究

Signaling pathway of thyroid hormone on the promotion of tumor cell proliferation and angiogenesis

目的 探讨甲状腺激素促进肿瘤细胞增殖及血管新生的信号通路.方法 体外培养人胶质母细胞瘤细胞系（SNB19）,给予甲状腺激素（主要为T4,100 nmol/L）、四碘甲腺乙酸（tetraiodothyroacetic acid,Tetrac,100 nmol/L）、蛋白激酶C（PKC）抑制剂（2.5 μmol/L）作用后,采用Western印迹方法检测磷酸化蛋白激酶D1（PKD1）、磷酸化组蛋白去乙酰化酶（HDAC）5、磷酸化细胞外信号调节激酶（ERK）1/2的表达,ELISA方法检测细胞培养上清血管内皮生长因子（VEGF）的表达量,3-（4,5）-2-唑噻-（2,5）-二苯基溴化四氮唑蓝（MTT）比色法检测细胞增殖.结果 与对照组相比,T4干预组磷酸化PKD1、磷酸化HDAC5、磷酸化ERK1/2水平均增加（P均＜0.05）,Tetrac干预组及PKC抑制剂干预组磷酸化PKD1、磷酸化HDAC5、磷酸化ERK1/2水平均降低（P均＜0.05）.ELISA结果显示,与对照组相比,T4干预组VEGF浓度升高[（56.763±2.611） ng/L vs.（36.597±0.933） ng/L,P＜0.05],Tetrac＋T4干预组VEGF浓度降低[（22.215±1.531） ng/L vs.（36.597±0.933） ng/L,P＜0.05].MTT结果显示,与对照组相比,T4干预组OD值较高[（0.333±0.020）vs.（0.243±0.006）,P＜0.05],Tetrac干预组OD值较低[（0.060±0.016） vs.（0.243±0.006）,P＜0.05].结论 甲状腺激素通过结合整合素αvβ3,激活ERK1/2信号通路促进肿瘤细胞增殖,激活PKC/PKD1/HDAC5信号通路促进血管新生.

Objective To study the signaling pathway of proliferation and angiogenesis of tumor cells promoted by thyroid hormone.Methods Human glioblastoma cells（SNB 19） were cultured with thyroid hormone （mainly T4,100 nmol/L）,tetraiodothyroacetic acid （Tetrac,100 nmol/L） or protein kinase C （PKC） inhibitor （2.5 μmol/L）in vitro.The expression of phosphorylated protein kinase D 1 （PKD1）,phosphorylated histone deacetylase （HDAC）5 and phosphorylated extracellular regulated protein kinases （ERK）1/2 were detected by Western blots.The expression of vascular endothelial growth factor （VEGF） in supernatant was measured by ELISA.The proliferation of SNB19 cells was detected by 3-（4,5-Dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） colorimetric method.Results Compared with control group,phosphorylated PKD1,phosphorylated HDAC5 and phosphorylated ERK1/2 were all increased in T4 group （all P〈0.05）,and decreased in Tetrac＋T4 group and PKC inhibitor group （all P 〈0.05）.The concentration of VEGF in T4 group was enhanced [（56.763 ± 2.611） ng/L vs.（36.597 ± 0.933） ng/L,P 〈0.05],while reduced in Tetrac＋T4 group [（22.215 ± 1.531） ng/L vs.（36.597 ± 0.933） ng/L,P 〈0.05],compared with control group.The results of MTT showed that compared with control group,the OD value of T4 group was enhanced[（0.333 ± 0.020） vs.（0.243 ± 0.006）,P〈0.05],and reduced in Tetrac＋T4 group[（0.060 ± 0.016） vs.（0.243 ± 0.006）,P〈0.05].Conclusion Through binding to membrane integrin αvβ3,thyroid hormone promotes the proliferation of tumor cells by activating the ERK1/2 signaling pathway,and promotes angiogenesis by activating the PKC/PKD1/HDAC5 signaling pathway.